How Cannabis Affects Health

Cannabis, like other drugs, can be harmful to your health. The risks are increased when use begins in the teen years and when cannabis is used on a daily or near-daily basis. People with a history of drug and/or mental health problems are also at an increased risk for experiencing harms related to cannabis use.

What are the short-term risks of using cannabis?

Cannabis has different effects on different people which vary depending on many factors including the type and amount of product used. Some people who use cannabis may feel relaxed and happy. Others may become quiet and withdrawn or experience anxiety, panic attacks, fearfulness and paranoia.

Some of the immediate physical effects of cannabis are red eyes, increased heart rate, drop in blood pressure, and light-headedness. When high on cannabis people may also experience altered senses (for example, seeing brighter colors), altered sense of time, reduced balance and coordination, difficulty with thinking and problem-solving and difficulty remembering things. These effects usually disappear within a few hours but can last longer, especially if the drug is consumed in edible form.

Cannabis use impairs your ability to drive safely and to operate equipment. It can also increase the risk of falls and other injuries, especially when you are doing higher-speed activities such as cycling, skiing or snowboarding. This is because THC can affect a person’s:

Regular use of cannabis during the teen years can harm the developing brain and is linked to the development of psychosis and/or schizophrenia in certain people and with other mental health issues such as depression and anxiety. Regular use of cannabis has been shown to negatively impact a teen’s perception, memory, judgment, and reasoning. These changes can reduce a young person’s motivation and school performance, as well as negatively affecting decision making and increasing risk taking behaviour.

Your Lungs

Regular use of cannabis can affect your lungs and lead to conditions such as cough, wheeze, worsening of asthma, sore throat, bronchitis, and lung infections. Cannabis smoke contains many of the same chemicals as tobacco smoke, several of which are known to cause cancer.

While many people think that you cannot become addicted to cannabis, it's estimated that 1 in 11 (9%) cannabis users will develop an addiction to it. This statistic rises to about 1 in 6 (17%) for people who started using cannabis as a teenager. If a person smokes cannabis daily, the risk of addiction is 25% to 50%. (Health Canada 2017)

Individuals who develop an addiction to cannabis typically:

Want to use all the time - even when they didn't plan to

Spend a lot of time thinking about and using cannabis

Need a greater amount of cannabis to get the same effects

Continue to use cannabis even though it is causing physical or social problems